Avalanche Forecast
Issued: Nov 16th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Storm Slabs and Loose Dry.
Aaron Beardmore,
Although the storm has passed and the temperatures have cooled, large avalanches were directly observed today. The storm snow needs more time to settle and bond.
Summary
Weather Forecast
Cooler temperatures are expected over the next few days with valley temps staying below zero. Minimal precip associated with a benign weather pattern is expected. The wind could be the most intense input with wind speed well in to strong range from the West on Thursday.
Snowpack Summary
Up to 80cm of storm snow since Friday with moderate SW winds have created windslabs in the alpine and at treeline and storm slabs at all elevations. This buries a relatively thin, facetted snowpack with a couple crusts in it. Total snow depths are 60-100cm at treeline with more in the alpine. Below 2000m, rain has saturated the snowpack.
Avalanche Summary
Forecasters observed the remnants of the cycle that ended with the cooling of temperatures this morning. Storms slabs up to size 3.5 were observed throughout Banff, Yoho and Kootenay highway corridors. Today, Lake Louise reported triggering a size 3 avalanche 250m wide on the Nov 5th crust using explosives.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
Conditions from the recent storm have formed wind slabs, predominantly in the alpine, but also in some treeline areas. These will take a few more days to heal following the first major storm of the winter.
- Watch for surface cracking and stiffer surface layers of snow. Avoid wind loaded terrain.
- Use caution in lee areas. Recent wind loading have created wind slabs.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
The recent storm cycle has created widespread storm slabs. This problem still needs time to settle and bond, so treat steep open slopes at treeline and in the alpine as suspect.
- Make observations and assess conditions continually as you travel.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Up to 70 cm of recent storm snow is available to run as loose dry avalanches from steep terrain. Watch out for increased sluffing if the wind picks up or changes direction.
- Be careful of loose dry sluffing in steep, confined or exposed terrain.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Nov 17th, 2021 4:00PM
